U.S. patent application number 16/385201 was filed with the patent office on 2019-12-05 for controller for rotary electric machine.
This patent application is currently assigned to Mitsubishi Electric Corporation. The applicant listed for this patent is Mitsubishi Electric Corporation. Invention is credited to Kenichi AKITA, Masahiko Fujita, Norio Matsumoto, Mitsunori Tabata, Toshiyuki Yoshizawa.
Application Number | 20190372499 16/385201 |
Document ID | / |
Family ID | 67212209 |
Filed Date | 2019-12-05 |
United States Patent
Application |
20190372499 |
Kind Code |
A1 |
AKITA; Kenichi ; et
al. |
December 5, 2019 |
CONTROLLER FOR ROTARY ELECTRIC MACHINE
Abstract
To provide a controller for a rotary electric machine capable of
suppressing occurrence of an angle interval when the rotary
electric machine cannot output torque, even if the ON angle
interval of the switching devices is set smaller than 120 degrees
in the rectangular wave control. A controller for a rotary electric
machine performs a rectangular wave control to a rotary electric
machine which has 2 groups of three-phase windings, with a phase
difference between groups; and switches a first control mode and a
second control mode according to a switching condition; wherein the
first control mode is a mode which sets an ON angle interval to an
angle within a range from 120 degrees to 180 degrees; and wherein
the second control mode is a mode which sets the ON angle interval
to an angle within a range from 90 degrees to 120 degrees.
Inventors: |
AKITA; Kenichi; (Tokyo,
JP) ; Fujita; Masahiko; (Tokyo, JP) ;
Matsumoto; Norio; (Tokyo, JP) ; Yoshizawa;
Toshiyuki; (Tokyo, JP) ; Tabata; Mitsunori;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Mitsubishi Electric Corporation |
Tokyo |
|
JP |
|
|
Assignee: |
Mitsubishi Electric
Corporation
Tokyo
JP
|
Family ID: |
67212209 |
Appl. No.: |
16/385201 |
Filed: |
April 16, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02P 2209/00 20130101;
H02P 25/22 20130101; H02P 23/0027 20130101; H02P 27/085
20130101 |
International
Class: |
H02P 23/00 20060101
H02P023/00; H02P 27/08 20060101 H02P027/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2018 |
JP |
2018-104241 |
Claims
1. A controller for a rotary electric machine which has 2 groups of
three-phase windings, the controller for the rotary electric
machine comprising: an inverter that, for each group of the 2
groups, is provided with 3 sets of a series circuit where a
positive electrode side switching device connected to positive
electrode side of a DC power source and a negative electrode side
switching device connected to negative electrode side of the DC
power source are connected in series and where a connection node of
series connection is connected to the winding of the corresponding
phase, corresponding to respective phases of the three-phase; and a
switching controller that, for each group with a phase difference
between groups, performs a rectangular wave control that turns on
the positive electrode side switching device and the negative
electrode side switching device of each phase once per 360 degrees
in electrical angle respectively with a phase difference of 180
degrees in electrical angle between the positive electrode side and
the negative electrode side, with a phase difference of 120 degrees
in electrical angle between phases, wherein the switching
controller switches a first control mode and a second control mode
according to a preliminarily set switching condition; wherein the
first control mode is a mode which sets an ON angle interval, which
is an angle interval turning on the positive electrode side
switching device and the negative electrode side switching device,
to an angle within a range from 120 degrees to 180 degrees in
electrical angle; and wherein the second control mode is a mode
which sets the ON angle interval to an angle within a range from 90
degrees to 120 degrees in electrical angle.
2. The controller for the rotary electric machine according to
claim 1, wherein when the phase difference between groups of the
rectangular wave control is set to an angle within a range from 0
degree to 60 degrees in electrical angle, the switching controller,
in the second control mode, sets the ON angle interval to an angle
within a range from a lower limit ON angle interval to 120 degrees,
wherein the lower limit ON angle interval is obtained by adding an
absolute value of a value subtracting 30 degrees from the phase
difference between groups, to 90 degrees; and when the phase
difference between groups is set to an angle within a range from 60
degrees to 120 degrees in electrical angle, the switching
controller, in the second control mode, sets the ON angle interval
to an angle within a range from a lower limit ON angle interval to
120 degrees, wherein the lower limit ON angle interval is obtained
by adding an absolute value of a value subtracting 90 degrees from
the phase difference between groups, to 90 degrees.
3. The controller for the rotary electric machine according to
claim 1, wherein when the phase difference between groups is set to
an angle within a range from 0 degrees to 60 degrees in electrical
angle, the switching controller, in the second control mode, sets
the ON angle interval to a lower limit ON angle interval, wherein
the lower limit ON angle interval is obtained by adding an absolute
value of a value subtracting 30 degrees from the phase difference
between groups, to 90 degrees; and when the phase difference
between groups is set to an angle within a range from 60 degrees to
120 degrees in electrical angle, the switching controller, in the
second control mode, sets the ON angle interval to a lower limit ON
angle interval, wherein the lower limit ON angle interval is
obtained by adding an absolute value of a value subtracting 90
degrees from the phase difference between groups, to 90
degrees.
4. The controller for the rotary electric machine according to
claim 1, wherein the switching controller sets the phase difference
between groups to 30 degrees or 90 degrees in electrical angle, and
sets the ON angle interval to 90 degrees in electrical angle in the
second control mode.
5. The controller for the rotary electric machine according to
claim 1, wherein the phase difference between groups of the
rectangular wave control is set to the phase difference between
groups of the three-phase windings.
6. The controller for the rotary electric machine according to
claim 1, wherein the switching controller switches the first
control mode and the second control mode according to a rotational
speed of the rotary electric machine and a power source voltage of
the DC power source as the switching condition.
7. The controller for the rotary electric machine according to
claim 1, further comprising a chip temperature detector that
detects a temperature of the switching device, wherein the
switching controller switches the first control mode and the second
control mode according to the temperature of the switching device
as the switching condition.
8. The controller for the rotary electric machine according claim
1, wherein the switching controller changes the ON angle interval
gradually, when changing the ON angle interval.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of Japanese Patent Application No.
2018-104241 filed on May 31, 2018 including its specification,
claims and drawings, is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] The present disclosure relates to a controller for a rotary
electric machine which performs rectangular wave control.
[0003] In recent years, for the purpose of improvement in fuel
efficiency and adaptation to the environmental standard, so-called
idling stop vehicle that mounts the rotary electric machine, stops
the engine at the stop of vehicle, drives the rotary electric
machine at the start of vehicle, and performs the restart and the
torque assist of the engine has been developed. Since small size,
low cost, and high torque are required for the rotary electric
machine used for such a vehicle, the rectangular wave control of
180 degrees which can simplify the controller and attain the high
power of the rotary electric machine is used in many cases, as a
method which controls on and off of the switching devices. In the
rectangular wave control of 180 degrees, the ON angle interval of
the switching devices is set to 180 degrees in electrical angle. A
higher power of the rotary electric machine is required for the
improvement in fuel efficiency, for that purpose, higher capacity
and higher voltage of the vehicle power supply device (vehicle
battery) are implemented.
[0004] However, on the other hand, since the rectangular wave
control does not perform feedback control of energizing current to
the armature winding at driving, there was anxiety of failure due
to current which exceeded the tolerance of the switching devices
and heat generation at energization, depending on operating
conditions, such as the rotational speed and the power source
voltage. Then, as a method to suppress the energizing current at
performing the rectangular wave control, the method of performing
the rectangular wave control of 120 degrees, in which the
energizing current decreases rather than the rectangular wave
control of 180 degrees, on the condition where the energizing
current becomes excessive has been proposed (for example, refer to
JP 2004-320861 A). In the rectangular wave control of 120 degrees,
the ON angle interval of the switching devices is set to 120
degrees in electrical angle.
SUMMARY
[0005] However, as mentioned above, higher capacity and higher
voltage of the vehicle battery are advancing in recent years; when
the rectangular wave control is performed, in the low rotation
speed region where the energizing time of 1 pulse at performing the
rectangular wave control becomes long in particular, only by the
conventional technology which reduces the ON angle interval of the
switching devices to 120 degrees, the energizing current to the
power conversion portion becomes large, and there was still anxiety
of causing failure due to heat generation at energization and the
like.
[0006] In order to reduce the heat generation of the switching
devices, it is considered to reduce the ON angle interval of the
switching devices less than 120 degrees in electrical angle.
However, in the case where the rotary electric machine is provided
with only 1 group of three-phase windings as JP 2004-320861 A, if
the ON angle interval is reduced less than 120 degrees, intervals
when only one of the positive electrode side switching device and
the negative electrode side switching device is turned on will
occur. In this interval, since current does not flow through
winding, the rotary electric machine cannot output torque. For
example, when a rotary electric machine stops in this torque output
impossible interval, the rotary electric machine cannot output
torque, the internal combustion engine cannot be restarted, and the
vehicle cannot be started. Also in the state where the rotary
electric machine is rotating, torque fluctuation becomes large and
there is a possibility of giving a user discomfort.
[0007] Thus, it is desirable to provide a controller for a rotary
electric machine capable of suppressing occurrence of an angle
interval when the rotary electric machine cannot output torque,
even if the ON angle interval of the switching devices is set
smaller than 120 degrees in electrical angle in the rectangular
wave control.
[0008] A controller for a rotary electric machine which has 2
groups of three-phase windings according to the present disclosure,
the controller for the rotary electric machine including:
[0009] an inverter that, for each group of the 2 groups, is
provided with 3 sets of a series circuit where a positive electrode
side switching device connected to positive electrode side of a DC
power source and a negative electrode side switching device
connected to negative electrode side of the DC power source are
connected in series and where a connection node of series
connection is connected to the winding of the corresponding phase,
corresponding to respective phases of the three-phase; and
[0010] a switching control unit that performs, for each group with
a phase difference between groups, a rectangular wave control that
turns on the positive electrode side switching device and the
negative electrode side switching device of each phase respectively
once per 360 degrees in electrical angle with a phase difference of
180 degrees in electrical angle mutually, with a phase difference
of 120 degrees in electrical angle between phases,
[0011] wherein the switching control unit switches a first control
mode and a second control mode according to a preliminarily set
switching condition; wherein the first control mode is a mode which
sets an ON angle interval, which is an angle interval turning on
the positive electrode side switching device and the negative
electrode side switching device, to an angle within a range from
120 degrees to 180 degrees in electrical angle; and wherein the
second control mode is a mode which sets the ON angle interval to
an angle within a range from 90 degrees to 120 degrees in
electrical angle.
[0012] According to the controller for the rotary electric machine
of the present disclosure, the rectangular wave control can be
operated not only in the first control mode of from 120 degrees to
180 degrees in electrical angle which can be performed in the case
of providing 1 group of three-phase windings, but also in the
second control mode where the ON angle interval is set to an angle
within the range from 90 degrees to 120 degrees in electrical angle
according to the switching condition, by utilizing that the 2
groups of three-phase windings are provided. Even operating in the
second control mode, by providing the phase difference between the
first group of rectangular wave control and the second group of
rectangular wave control, the torque output impossible interval of
the one group can be compensated by the torque output possible
interval of the other group, and it is possible to suppress
occurrence of angle intervals when the rotary electric machine
cannot output torque. Therefore, by switching to the second control
mode, while suppressing the heat generation of the switching
devices, the rotary electric machine can output torque.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic configuration diagram of the rotary
electric machine and the controller for the rotary electric machine
according to Embodiment 1;
[0014] FIG. 2 is a schematic block diagram of the control device
according to Embodiment 1;
[0015] FIG. 3 is a hardware configuration diagram of the control
device according to Embodiment 1;
[0016] FIG. 4 is a figure showing behavior of the rectangular wave
control when the ON angle interval is set to 180 degrees according
to Embodiment 1;
[0017] FIG. 5 is a figure showing behavior of the rectangular wave
control when the ON angle interval is set to 120 degrees according
to Embodiment 1;
[0018] FIG. 6 is a figure showing behavior of the rectangular wave
control when the ON angle interval is set to 90 degrees according
to Embodiment 1;
[0019] FIG. 7 is a figure showing behavior of the rectangular wave
control when the ON angle interval is set to 90 degrees according
to Embodiment 1;
[0020] FIG. 8 is a figure explaining the angle setting map
according to Embodiment 1;
[0021] FIG. 9 is a figure explaining the angle setting map
according to Embodiment 1;
[0022] FIG. 10 is a schematic configuration diagram of the rotary
electric machine and the controller for the rotary electric machine
according to Embodiment 2; and
[0023] FIG. 11 is a schematic block diagram of the control device
according to Embodiment 2.
DETAILED DESCRIPTION OF THE EMBODIMENTS
1. Embodiment 1
[0024] A controller 1 for a rotary electric machine (hereinafter,
referred to simply as the controller 1) according to Embodiment 1
will be explained with reference to drawings. FIG. 1 is a schematic
configuration diagram of the rotary electric machine 10 and the
controller 1 according to the present embodiment.
1-1. Rotary Electric Machine
[0025] The rotary electric machine 10 is one rotary electric
machine which has 2 groups of three-phase windings 11, 12. The
first group of three-phase windings 11 is windings Cu, Cv, Cw of U,
V, and W phases, and the second group of three-phase windings 12 is
windings Cx, Cy, Cz of X, Y, and Z phases. The first group of
three-phase windings 11 and the second group of three-phase
windings 12 are wound around the stator 13 with a phase difference
.DELTA..theta.CL in electrical angle. Specifically, there is a
winding phase difference .DELTA..theta.CL in electrical angle
between the winding angle of the first group of U phase winding Cu
and the winding angle of the second group of X phase winding Cx;
there is a winding phase difference .DELTA..theta.CL in electrical
angle between the winding angle of the first group of V phase
winding Cv and the winding angle of the second group of Y phase
winding Cy; and there is a winding phase difference
.DELTA..theta.CL in electrical angle between the winding angle of
the first group of W phase winding Cw and the winding angle of the
second group of Z phase winding Cz.
[0026] The electromagnet is provided in the rotor 14. Therefore,
the 2 groups of three-phase windings 11, 12 are provided in the one
stator 13, and the electromagnet is provided in the one rotor 14
which is disposed at the radial-direction inner side of the stator
13. The electrical angle becomes an angle obtained by multiplying
the number of pole pairs of the electromagnet to the mechanical
angle of the rotor 14. The rotary electric machine 10 is provided
with a rotation angle sensor 15, such as a resolver and a rotary
encoder, for detecting a rotational angle (magnetic pole position)
of the rotor 14. An output signal of the rotation angle sensor 15
is inputted into a control device 30.
1-2. Inverter
[0027] The controller 1 is provided with a first group of inverter
21 which converts the DC power of the DC power source 16 and the AC
power supplied to the first group of three-phase windings 11, and a
second group of inverter 22 which converts the DC power of the DC
power source 16 and the AC power supplied to the second group of
three-phase windings 12.
[0028] Each of the first group and the second group of inverter 21,
22 is provided with three sets of a series circuit where a positive
electrode side switching device 23 connected to the positive
electrode side of the DC power source 16 and a negative electrode
side switching device 24 connected to the negative electrode side
of the DC power source 16 are connected in series, corresponding to
respective phase of the three-phase windings. A connection node of
two switching devices in each series circuit is connected to the
winding of the corresponding phase. The inverter is provided with a
switching device which turns on and off energization to a field
winding of the electromagnet (unillustrated).
[0029] MOSFET (Metal Oxide Semiconductor Field Effect Transistor)
IGBT (Insulated Gate Bipolar Transistor) in which a diode is
connected in reversely parallel, and the like is used for the
switching devices. A gate terminal of each switching device is
connected to the control device 30 via a gate drive circuit and the
like. Therefore, each switching device is turned on or turned off
by a gate signal outputted from the control device 30.
[0030] An electricity accumulation device, such as a lead battery
and a lithium ion battery, is used for the DC power source 16. A
DC-DC converter which is a DC electric power converter which steps
up or steps down the DC voltage may be provided in the DC power
source 16. A voltage sensor 17 for detecting a power source voltage
of the DC power source 16 is provided. An output signal of the
voltage sensor 17 is inputted into the control device 30.
[0031] In the present embodiment, a rotary shaft of the rotor 14 of
the rotary electric machine 10 is connected with a crankshaft of an
internal combustion engine 18 via a connecting mechanism, such as a
belt and a pulley mechanism. The rotary electric machine 10 has a
function as a motor to start or assist the internal combustion
engine 18, and has a function as a generator which generates
electricity using the driving force of the internal combustion
engine 18.
1-3. Control Device
[0032] The controller 1 is provided with a control device 30. The
control device 30 controls the rotary electric machine 10 via the
switching devices of the first group and the second group of
inverters 21, 22. The control device 30 is provided with control
units, such as a rotation information detection unit 31, a power
source voltage detection unit 32, and a switching control unit 33,
as shown in FIG. 2. Respective functions of the control device 30
are realized by processing circuits provided in the control device
30. Specifically, as shown in FIG. 3, the control device 30 is
provided, as processing circuits, with an arithmetic processor
(computer) 90 such as a CPU (Central Processing Unit), storage
apparatuses 91 which exchange data with the arithmetic processor
90, an input circuit 92 which inputs external signals to the
arithmetic processor 90, an output circuit 93 which outputs signals
from the arithmetic processor 90 to the outside, and the like.
[0033] As the arithmetic processor 90, ASIC (Application Specific
Integrated Circuit), IC (Integrated Circuit), DSP (Digital Signal
Processor), FPGA (Field Programmable Gate Array), various kinds of
logical circuits, various kinds of signal processing circuits, and
the like may be provided. As the arithmetic processor 90, a
plurality of the same type ones or the different type ones may be
provided, and each processing may be shared and executed. As the
storage apparatuses 91, there are provided a RAM (Random Access
Memory) which can read data and write data from the arithmetic
processor 90, a ROM (Read Only Memory) which can read data from the
arithmetic processor 90, and the like. The input circuit 92 is
connected with various kinds of sensors and switches such as the
rotation angle sensor 15 and the voltage sensor 17, and is provided
with an A/D converter and the like for inputting output signals
from the sensors and the switches to the arithmetic processor 90.
The output circuit 93 is connected with electric loads such as a
gate drive circuit which drive on and off of the switching devices
of the first group and the second group of inverters 21, 22, and is
provided with a driving circuit and the like for outputting a
control signal from the arithmetic processor 90.
[0034] Then, the arithmetic processor 90 runs software items
(programs) stored in the storage apparatus 91 such as a ROM and
collaborates with other hardware devices in the control device 30,
such as the storage apparatus 91, the input circuit 92, and the
output circuit 93, so that the respective functions of the control
units 31 through 33 provided in the control device 30 are realized.
Setting data items such as an angle setting map to be utilized in
the control units 31 through 33 are stored, as part of software
items (programs), in the storage apparatus 91 such as a ROM. Each
function of the control device 30 will be described in detail
below.
1-3-1. Rotation Information Detection Unit 31
[0035] The rotation information detection unit 31 detects a
rotational angle .theta. (a magnetic pole position .theta.) and a
rotational speed in electrical angle of the rotor 14. In the
present embodiment, the rotation information detection unit 31
detects the rotational angle .theta. (the magnetic pole position
.theta.) and the rotational speed based on the output signal of the
rotation angle sensor 15.
1-3-2. Power Source Voltage Detection Unit 32
[0036] The power source voltage detection unit 32 detects a power
source voltage of the DC power source 16. In the present
embodiment, the power source voltage detection unit 32 detects the
power source voltage based on the output signal of the voltage
sensor 17.
1-3-3. Switching Control Unit 33
[0037] The switching control unit 33 performs PWM (Pulse Width
Modulation) control which controls on and off of the switching
devices for each group. In the present embodiment, as shown in FIG.
4, the switching control unit 33 performs, for each group, a
rectangular wave control that turns on the positive electrode side
switching device 23 and the negative electrode side switching
device 24 of each phase once per 360 degrees respectively in
electrical angle with a phase difference of 180 degrees in
electrical angle between the positive electrode side switching
device 23 and the negative electrode side switching device 24 of
each phase, with a phase difference of 120 degrees in electrical
angle between phases. For example, about U phase, the phase
difference of 180 degrees in electrical angle is set between the ON
period of the positive electrode side switching device 23 and the
ON period of the negative electrode side switching device 24. The
ON period of the positive electrode side switching device 23 of V
phase is delayed by the phase difference of 120 degrees in
electrical angle to the ON period of the positive electrode side
switching device 23 of U phase. The ON period of the positive
electrode side switching device 23 of W phase is delayed by the
phase difference of 120 degrees in electrical angle to the ON
period of the positive electrode side switching device 23 of V
phase.
[0038] As described later, the switching control unit 33 changes an
ON angle interval .DELTA..theta.on which is an angle interval
turning on the positive electrode side switching device 23 and the
negative electrode side switching device 24. In the example of FIG.
4, the ON angle interval .DELTA..theta.on is set to 180 degrees in
electrical angle.
[0039] The switching control unit 33, for each group, totally
shifts a phase of the ON period of each switching device to the
advance angle side or the delay angle side in order to change the
output torque. By shifting the phases of all ON periods to the
advance angle side or the delay angle side, the magnitude of the
output torque of the rotary electric machine 10 can be changed, and
not only positive power running torque but also negative
regenerative torque can be outputted by the rotary electric machine
10. The phases of all ON periods may not be shifted but may be
fixed. The switching control unit 33 changes an ON duty ratio of
the switching device which turns on and off energization to the
field winding of the electromagnet in order to change the output
torque.
[0040] The switching control unit 33 performs the rectangular wave
control with the phase difference .DELTA..theta.p between groups.
For example, as shown in FIG. 4, the phase difference
.DELTA..theta.p (in this example, 30 degrees in electrical angle)
between groups is set between the ON period of the positive
electrode side switching device 23 of U phase of the first group,
and the ON period of the positive electrode side switching device
23 of X phase of the second group.
[0041] In the present embodiment, the first group of rectangular
wave control is performed based on the rotational angle .theta. on
the basis of first group of three-phase windings Cu, Cv, Cw (for
example, U phase winding Cu); and the second group of rectangular
wave control is performed based on the rotational angle .theta. on
the basis of second group of three-phase windings Cx, Cy, Cz (for
example, X phase winding Cx). Accordingly, in the present
embodiment, the phase difference .DELTA..theta.p between groups is
the same as the winding phase difference .DELTA..theta.CL (in this
example, 30 degrees in electrical angle)
(.DELTA..theta.p=.DELTA..theta.CL=30 degrees). Alternatively, the
phase difference .DELTA..theta.p between groups may change from the
winding phase difference .DELTA..theta.CL.
<Problem of Reduction of ON Angle Interval
.DELTA..theta.on>
[0042] The maximum set value of the ON angle interval
.DELTA..theta.on is 180 degrees in electrical angle. This is
because if the ON angle interval .DELTA..theta.on is set larger
than 180 degrees, the positive electrode side and the negative
electrode side switching devices 23, 24 of each phase are turned on
at the same time, and a period which the positive electrode side
and the negative electrode side of the DC power source 16 are
short-circuited occurs.
[0043] If the ON angle interval .DELTA..theta.on is large, the ON
period of each switching device becomes long, and the heat
generation of the switching device becomes large by continuous
energization. In particular, the lower the rotational speed
becomes, the longer the ON period of the switching device becomes
and the larger the heat generation of the switching device becomes
even with the same ON angle interval .DELTA..theta.on. The larger
the power source voltage becomes, the larger the current value
becomes and the larger the heat generation of the switching device
becomes even at the same ON angle interval .DELTA..theta.on and the
same rotational speed. In order to reduce the heat generation of
the switching device, it is considered to reduce the ON angle
interval .DELTA..theta.on from 180 degree in electrical angle.
[0044] As FIG. 5 shows a case where the ON angle interval
.DELTA..theta.on is set to 120 degrees in electrical angle, since
both of the positive electrode side switching device and the
negative electrode side switching device are turned on in all
timing of 360 degrees in electrical angle in one group, current can
flow through the windings and the rotary electric machine 10 can
output torque.
[0045] However, if the ON angle interval .DELTA..theta.on is set
smaller than 120 degrees in electrical angle, as FIG. 6 shows a
case where the ON angle interval .DELTA..theta.on is set to 90
degrees in electrical angle, an interval (hatching part in FIG. 6)
when only one of the positive electrode side switching device and
the negative electrode side switching device is turned on occurs in
one group. In this interval, since current does not flow through
the windings, the rotary electric machine 10 cannot output torque
by the windings of one group. If the rotary electric machine 10
stops in this torque output impossible interval, the rotary
electric machine 10 cannot output torque, for example, the internal
combustion engine 18 cannot be restarted, and a vehicle cannot be
started.
[0046] Therefore, with a rotary electric machine which has only 1
group of three-phase windings, as conventional technology, the ON
angle interval .DELTA..theta.on could not be set smaller than 120
degrees in electrical angle, and there was a limit in reducing the
heat generation of the switching devices.
<Use of 2 Groups of Three-Phase Windings>
[0047] As shown in FIG. 6, when the ON angle interval
.DELTA..theta.on is 90 degrees in electrical angle, the torque
output impossible interval (hatching part) when only one of the
positive electrode side and the negative electrode side switching
devices is turned on becomes an interval of 30 degrees in
electrical angle, the torque output possible interval (non-hatching
part) when both of the positive electrode side and the negative
electrode side switching devices are turned on becomes an interval
of 30 degrees in electrical angle, and both become the same
interval. Accordingly, as shown in FIG. 6, by providing a phase
difference between the first group of rectangular wave control and
the second group of rectangular wave control, the torque output
impossible interval of one group can be compensated by the torque
output possible interval of the other group. If the ON angle
interval .DELTA..theta.on is set to smaller than 90 degrees in
electrical angle, the torque output impossible interval becomes
longer than the torque output possible interval, and the torque
output, impossible interval of one group cannot be compensated
enough by the torque output possible interval of the other group.
Therefore, the minimum value of the ON angle interval
.DELTA..theta.on in the case of providing the 2 groups of
three-phase windings becomes 90 degrees in electrical angle.
[0048] Then, as shown in a next equation, the switching control
unit 33 switches a first control mode and a second control mode
according to a preliminarily set switching condition. Wherein the
first control mode is a mode which sets the ON angle interval
.DELTA..theta.on to an angle within a range from 120 degrees to 180
degrees in electrical angle, and wherein the second control mode is
a mode which sets the ON angle interval .DELTA..theta.on to an
angle within a range from 90 degrees to 120 degrees in electrical
angle.
1) In the Case of the First Control Mode
[0049] 120<=.DELTA..theta.on<=180
2) In the Case of the Second Control Mode
[0050] 90<=.DELTA..theta.on<120 (1)
[0051] According to this configuration, the rectangular wave
control can be operated not only in the first control mode of from
120 degrees to 180 degrees in electrical angle which can be
performed in the case of providing 1 group of three-phase windings,
but also in the second control mode where the ON angle interval
.DELTA..theta.on is set to an angle within the range from 90
degrees to 120 degrees in electrical angle according to the
switching condition, by utilizing that the 2 groups of three-phase
windings are provided. Even operating in the second control mode,
by providing the phase difference between the first group of
rectangular wave control and the second group of rectangular wave
control, the torque output impossible interval of the one group can
be compensated by the torque output possible interval of the other
group, and it is possible to suppress occurrence of an angle
interval when the rotary electric machine cannot output torque.
Accordingly, even if the rotary electric machine stops at any
rotational angle, the rotary electric machine can output torque,
and apparatus such as the internal combustion engine and the
vehicle can be operated. Therefore, by switching to the second
control mode, while suppressing the heat generation of the
switching devices, the rotary electric machine can output
torque.
[0052] In the present embodiment, since the phase difference
.DELTA..theta.p between groups is 30 degrees in electrical angle,
the torque output impossible interval of one group and the torque
output possible interval of the other group can be coincided
exactly and can be compensated completely with each other. As shown
in FIG. 7, also when the phase difference .DELTA..theta.p between
groups is 90 degrees in electrical angle, it can be coincided
similarly to the case of 30 degrees. Although the next coincided
phase difference .DELTA..theta.p between groups is 150 degrees in
electrical angle, since it becomes larger than 120 degrees and the
phase is exchanged, it becomes the same as 30 degrees in electrical
angle.
<Correspondence to Any Phase Difference .DELTA..theta.p Between
Groups>
[0053] On the other hand, if the phase difference .DELTA..theta.p
between groups deviates from 30 degrees and 90 degrees, the torque
output impossible interval of one group and the torque output
possible interval of the other group are not coincided exactly, and
gaps in which these are not coincided are caused. In order to
compensate these gaps, it is necessary to increase the ON angle
interval .DELTA..theta.on by a deviation width from 90 degrees. A
next equation expresses a minimum ON angle interval
.DELTA..theta.onmin (hereinafter, referred to as a lower limit ON
angle interval .DELTA..theta.onmin) that does not cause the gaps in
which the torque output impossible interval of one group and the
torque output possible interval of the other group are not
coincided, when the phase difference .DELTA..theta.p between groups
deviates from 30 degrees and 90 degrees in electrical angle.
1) In the Case of 0<.DELTA..theta.p<60
.DELTA..theta.onmin=90+|.DELTA..theta.p-30|
2) In the Case of 60<.DELTA..theta.p<120
.DELTA..theta.onmin=90+|.DELTA..theta.p-90| (2)
[0054] Then, in order to correspond to any phase difference
.DELTA..theta.p between groups, as shown in the equation (2) and a
next equation, when the phase difference .DELTA..theta.p between
groups is set to an angle within a range from 0 degree to 60
degrees in electrical angle, the switching control unit 33 sets, in
the second control mode, the ON angle interval .DELTA..theta.on to
an angle within a range from a lower limit ON angle interval
.DELTA..theta.onmin to 120 degrees. Wherein the lower limit ON
angle interval .DELTA..theta.onmin is obtained by adding an
absolute value of a value subtracting 30 degrees from the phase
difference .DELTA..theta.p between groups, to 90 degrees. On the
other hand, when the phase difference .DELTA..theta.p between
groups is set to an angle within a range from 60 degrees to 120
degrees in electrical angle, the switching control unit 33 sets, in
the second control mode, the ON angle interval .DELTA..theta.on to
an angle within a range from a lower limit ON angle interval
.DELTA..theta.onmin to 120 degrees. Wherein the lower limit ON
angle interval .DELTA..theta.onmin is obtained by adding an
absolute value of a value subtracting 90 degrees from the phase
difference .DELTA..theta.p between groups, to 90 degrees.
1) In the Case of the First Control Mode
[0055] 120<=.DELTA..theta.on<-180
2) In the Case of the Second Control Mode
[0056] .DELTA..theta.onmin<=.DELTA..theta.on<120 (3)
[0057] According to this configuration, in the second control mode,
to any phase difference .DELTA..theta.p between groups, it can
suppress causing the gaps in which the torque output possible
interval of one group and the torque output impossible interval of
the other group are not coincided. Therefore, while suppressing
causing the angle interval when the rotary electric machine cannot
output torque, it can suppress the heat generation of the switching
devices.
[0058] Alternatively, as shown in the next equation, in the second
control mode, the switching control unit 33 may set the lower limit
ON angle interval .DELTA..theta.onmin calculated by the equation
(2), to the ON angle interval .DELTA..theta.on.
1) In the Case of the First Control Mode
[0059] 120<=.DELTA..theta.on<=180
2) In the Case of the Second Control Mode
[0060] .DELTA..theta.on=.DELTA..theta.onmin (4)
[0061] According to this configuration, in second control mode,
while suppressing causing the angle interval when the rotary
electric machine cannot output torque, it can maximally suppress
the heat generation of the switching devices.
<Switching Condition>
[0062] In the present embodiment, the switching control unit 33
switches the first control mode and the second control mode
according to the rotational speed of the rotary electric machine
and the power source voltage of the DC power source as the
switching condition.
[0063] For example, the switching control unit 33 calculates the ON
angle interval .DELTA..theta.on corresponding to the present
rotational speed and the present power source voltage, by referring
to an angle setting map in which the relationship among the
rotational speed, the power source voltage, and the ON angle
interval .DELTA..theta.on is preliminarily set as shown in FIG. 8.
In the example shown in FIG. 8, in a region where the rotational
speed is lower than the boundary value, .DELTA..theta.on is set to
90 degrees, and it switches to the second control mode; and in a
region higher than the boundary value, .DELTA..theta.on is set to
180 degrees, and it switches to the first control mode. As the
power source voltage becomes higher, the boundary value shifts to
the high speed side, and the rotational speed region where
.DELTA..theta.on is set to 90 degrees expands to the high speed
side.
[0064] In this way, since, in the region of low rotational speed
and high power source voltage where the heat generation of the
switching devices becomes high, .DELTA..theta.on is set to 90
degrees and it switches to the second control mode, the heat
generation of the switching devices can be reduced.
[0065] Alternatively, the angle setting map may be set as shown in
FIG. 9. In the case of this example, the set region of
.DELTA..theta.on=120 degrees (the first control mode) is provided
between the set region of .DELTA..theta.on=90 degrees and the set
region of .DELTA..theta.on=180 degrees. In this way, according to
the necessity for reduction of the heat generation of the switching
devices, the ON angle interval .DELTA..theta.on may be gradually
decreased even in the same control mode.
[0066] The switching control unit 33 may change the ON angle
interval .DELTA..theta.on gradually, when changing the ON angle
interval .DELTA..theta.on. For example, when the ON angle interval
.DELTA..theta.on which was calculated by referring to the angle
setting map of FIG. 8 changes from 90 degrees to 180 degrees, the
time change rate of the ON angle interval .DELTA..theta.on is
limited, and the ON angle interval .DELTA..theta.on which is
finally set is gradually changed from 90 degrees to 180 degrees.
According to this configuration, a rapid change of the energizing
current and torque at switching can be suppressed.
2. Embodiment 2
[0067] Next, the controller 1 for the rotary electric machine
according to Embodiment 2 will be explained. The explanation for
constituent parts the same as those in Embodiment 1 will be
omitted. In the present embodiment, it is configured to detect the
temperature of the switching device, and the switching condition
which switches the first control mode and the second control mode
is different from Embodiment 1. FIG. 10 is a schematic
configuration diagram of the rotary electric machine 10 and the
controller 1 according to the present embodiment. FIG. 11 is a
block diagram of the control device 30 according to the present
embodiment.
[0068] In the present embodiment, as shown in FIG. 10, each of the
first group and the second group of inverters 21, 22 is provided
with the temperature sensor 25, 26 for detecting the temperature of
the switching device, respectively. Each temperature sensor 25, 26
is arranged close to the switching device, and can detect the
temperature of the switching device. The temperature sensor 25, 26
may be provided one by one for each phase of three phases, or the
temperature sensor 25, 26 may be provided one for only any one
phase of three phases. An output signal of each temperature sensor
25, 26 is inputted into the control device 30.
[0069] The control device 30 is further provided with a chip
temperature detection unit 34 which detects the temperature of the
switching device, as shown in FIG. 11. The chip temperature
detection unit 34 detects the temperature of the switching device
based on the output signal of each temperature sensor 25, 26.
[0070] The switching control unit 33 switches the first control
mode and the second control mode according to the temperature of
the switching device as the switching condition. Specifically, when
the temperature of the switching device is lower than a
preliminarily set switching determination value, the switching
control unit 33 performs the first control mode which sets the ON
angle interval aeon to an angle (for example, 180 degrees) within a
range from 120 degrees to 180 degrees in electrical angle. When the
temperature of the switching device is higher than or equal to the
switching determination value, the switching control unit 33
performs the second control mode which sets the ON angle interval
.DELTA..theta.on to an angle (for example, 90 degrees) within a
range from 90 degrees to 120 degrees in electrical angle. The
switching control unit 33 may use a maximum value or an average
value of temperatures of a plurality of switching devices which
were detected by the respective temperature sensors 25, 26.
[0071] According to this configuration, when the temperature of the
switching device becomes high, it is switched to the second control
mode, a temperature rise of the switching device can be suppressed,
and failure of the switching device due to overheating can be
suppressed.
Other Embodiments
[0072] Lastly, other embodiments of the present disclosure will be
explained. Each of the configurations of embodiments to be
explained below is not limited to be separately utilized but can be
utilized in combination with the configurations of other
embodiments as long as no discrepancy occurs.
[0073] (1) In each of the above-mentioned Embodiments, there has
been explained the case where the electromagnet is provided in the
rotor 14. However, embodiments of the present disclosure are not
limited to the foregoing case. That is to say, a permanent magnet
may be provided in the rotor 14, or a squirrel-cage type electric
conductor may be provided in the rotor 14.
[0074] (2) In each of the above-mentioned Embodiments, there has
been explained the case where the ON angle interval
.DELTA..theta.on in the second control mode is set to 90 degrees.
However, embodiments of the present disclosure are not limited to
the foregoing case. That is, the ON angle interval .DELTA..theta.on
in the second control mode may be set to an angle within the range
from 90 degrees to 120 degrees in electrical angle, for example,
100 degrees, 110 degrees, or the lower limit On angle interval
.DELTA..theta.onmin.
[0075] (3) In each of the above-mentioned Embodiments, there has
been explained the case where the phase difference .DELTA..theta.p
between groups is set to 30 degrees in electrical angle. However,
embodiments of the present disclosure are not limited to the
foregoing case. That is to say, the phase difference
.DELTA..theta.p between groups may be set to angles other than 30
degrees. In this case, as mentioned above, the ON angle interval
.DELTA..theta.on of the second control mode may be set according to
the equation (2) to (4).
[0076] (4) There has been explained the case where in the
Embodiment 1, the first control mode and the second control mode
are switched according to the rotational speed and the power source
voltage as the switching condition; and in the Embodiment 2, the
first control mode and the second control mode are switched
according to the temperature of the switching device as the
switching condition. However, embodiments of the present disclosure
are not limited to the foregoing case. That is to say, the
switching condition of the rotational speed and the power source
voltage and the switching condition of the temperature of the
switching device may be combined. For example, the switching
control unit 33 determines, as a base determination, to switch to
any of the first control mode and the second control mode according
to the rotational speed and the power source voltage; and even
though the result of base determination is switching to the first
control mode, when the temperature of the switching device is
higher than the switching determination value, the switching
control unit 33 finally determines to switch to the second control
mode.
[0077] Although the present disclosure is described above in terms
of various exemplary embodiments and implementations, it should be
understood that the various features, aspects and functionality
described in one or more of the individual embodiments are not
limited in their applicability to the particular embodiment with
which they are described, but instead can be applied, alone or in
various combinations to one or more of the embodiments. It is
therefore understood that numerous modifications which have not
been exemplified can be devised without departing from the scope of
the present disclosure. For example, at least one of the
constituent components may be modified, added, or eliminated. At
least one of the constituent components mentioned in at least one
of the preferred embodiments may be selected and combined with the
constituent components mentioned in another preferred
embodiment.
* * * * *